Field of the Invention
The present invention relates to a semiconductor device and a method for manufacturing the same, and more particularly to a semiconductor device used for an inverter or a regenerating converter to control a motor of an electric vehicle, an electric railcar, or the like, and a method for manufacturing the same.
Description of the Background Art
A conventional semiconductor device includes a ceramic substrate, circuit patterns arranged on the ceramic substrate, a semiconductor element packaged on the circuit pattern, and bonding wires to connect the circuit patterns, or the circuit pattern and the semiconductor element. The semiconductor device is provided with an insulating part in which the ceramic substrate is exposed, in order to insulate the circuit patterns from each other. A size of the ceramic substrate depends on an area of the circuit pattern and a width of the insulating part.
The ceramic substrate, the circuit patterns, the semiconductor element, and the bonding wires are sealed with an epoxy resin, for example. Adhesion properties between the ceramic substrate and the circuit pattern, and the epoxy resin are poor, so that resin sealing is performed after a polyimide resin or a polyamide-imide resin having low Young's modulus has been previously applied to the ceramic substrate in order to prevent the epoxy resin from being separated (refer to Japanese Patent Application Laid-Open No. 2006-32617, for example).
The conventional semiconductor device is configured as described above, so that in order to miniaturize the ceramic substrate, it is necessary to reduce the area of the circuit pattern or narrow the width of the insulating part, which causes the problem that assemblability and insulating properties are deteriorated.
In addition, in order to suppress separation of the epoxy resin, it is necessary to apply the resin having low Young's modulus, so that a step for the application is needed in a manufacturing process, which increases manufacturing costs. In a case where the resin having low Young's modulus is not applied to reduce the manufacturing costs, adhesion properties of the epoxy resin are deteriorated, and separation is generated. When the epoxy resin is separated, the problem is that a bonding lifetime of a component (such as an aluminum wire or a terminal) held by the epoxy resin is reduced, and the insulating properties are deteriorated between the circuit patterns on the ceramic substrate.